1. Field of the Invention
This invention relates to air bearings and in particular to an improved aerodynamic bearing.
2. Description of the Related Art
We refer to European Patent Applications 0732516A and 0732517A in the names of Sumitomo and of Sumitomo jointly with Canon respectively.
The first of these defines a varying gap between stator and rotor where a mathematical relationship is disclosed for an enlarged gap over a 60.degree. portion of the shaft. The second of these defines a gap formed by provision of flat faces along the peripheral surface of the shaft.
We also refer to publication WO94/28323 in which an air bearing is described and claimed comprising a plain cylindrical horizontal shaft rotatable in a non-circular bearing, wherein the developed form of the bearing surface into a substantially flat plane is a shallow sinusoidal wave having at least three wave peaks, the peak of one wave having a groove extending longitudinally of the bearing axis. In this arrangement the inner member rotates within an outer static member.